At least 34 people were killed when the most powerful earthquake to hit Mexico in decades tore through buildings, forced mass evacuations and triggered alerts as far away as Southeast Asia.

The 8.1 magnitude quake off the southern coast late on Thursday was stronger than a devastating 1985 tremor that flattened swathes of Mexico City and killed thousands. The quake was so strong that it caused buildings to sway violently in Mexico’s capital more than 1,000 km away.

The southern town of Juchitan in Oaxaca State, near the epicenter, was hit particularly hard, with sections of the town hall, a hotel, a bar and other buildings reduced to rubble.

“The situation is Juchitan is critical; this is the most terrible moment in its history,” the town’s mayor, Gloria Sanchez said, after the long, rumbling quake that also shook Guatemala and El Salvador.

The government said 25 people were killed in Oaxaca, and State governor Alejandro Murat said 17 of those were in Juchitan.

Casualty

A spokesman for emergency services said seven people died east of Oaxaca in the State of Chiapas, where thousands of people living on the coast were evacuated as a precaution when the quake sparked tsunami warnings.

Waves rose as high as 2.3 ft (0.7 m) in Mexico, the Pacific Tsunami Warning Center said, though that threat passed.

State oil company Pemex said it was checking for damage at its installations. President Enrique Pena Nieto said operations at the Salina Cruz refinery in the same region as the epicenter were temporarily suspended as a precautionary measure.

Two children died north of Chiapas in Tabasco state, the local governor said. At least 250 people in Oaxaca were also injured, according to agriculture minister Jose Calzada.

Authorities reported dozens of aftershocks, and President Pena Nieto said the quake was felt by around 50 million of Mexico’s roughly 120 million population, with further aftershocks likely. He advised people to check their homes and offices for damage and gas leaks.